This sounds like it is due to a bug in calendar association that was patched for the next release. Please see the answer in another thread here for more information and patch instructions: http://community.x2c...ser/#entry12612

Following up on the calendar issue: this issue is caused due to the use of an arrray_merge instead of the plus operator, which in turn squashes the keys of the associative array. You can patch your instance by updating both protected/modules/actions/views/actions/_actionForm.php and protected/modules/actions/views/actions/_form.php, around lines 82 and 307 respectively, to use the plus operator. After modifying, the code in question should read:

Regarding the calendar sync, are you able to see remote Google Calendar events in your X2 calendar? When you visit the calendar edit page, can you confirm that the remote calendar you chose is still associated to the calendar? What about your web server error log, or the X2 error log at protected/runtime/errors.log? Do either contain an error message or stack trace for that request?

I confirm that calendar sync works, I can view in the X2crm calendar section all the remote Google calendar records.

I am able to create/modify etc.. event in the X2crm calendar page and the record appears in the remote Google calendar (and vice versa).

The problem is when I create an action and I select a calendar that is associated to a Google calendar. The record is presented locally (in the X2crm calendar page) but no synchronization is performed.

I can confirm there is a bug present when syncing Actions created from the action create screen and not the calendar. This was due to Actions with an empty type being excluded from syncing. This has been resolved for the next release, thanks for reporting this issue!